Vertebrates

Characteristics of Vertebrates

Vertebrates have a vertebral column and specialized cells that develop from the nerve cord.

The vertebral column, or spinal column, is the hallmark feature of vertebrates.

Classes of vertebrates include fishes, amphibians, reptiles, birds, and mammals.

Vertebral ColumnA vertebral column made of cartilage or

bone surrounds and protects the dorsal nerve cord.

The vertebral column functions as a strong, flexible rod that muscles can pull against during swimming or running.

Neural CrestA neural crest is a group of cells that

develop from the nerve cord in vertebrates.

Portions of the brain and skull, certain sense organs, and some nerve fibers are some of the structures that develop from the neural crest.

Fish

Examples Jawless (eels), cartilagenous (sharks & rays), bony (goldfish, perch)

Habitat Water Warm & cold areas

Integument (covering) Scales, mucus

Respiratory System gills

Circulatory System 2 chamber heart

Body Temperature Regulation Ectothermic (cold blooded)- absorb heat from surroundings

Reproductive Fertilization & Embryo Development

External

Large # of eggs laid in water

Special Adaptations Swim bladder (depth in water)

Gills, fins, lateral line

FishJawless Fish (lampreys)

Cartilagenous (sharks, rays)

Bony (goldfish, perch)

Amphibians

Examples Frogs, toads, salamanders, legless

Habitat Freshwater, close to water, mostly warm areas

Integument (covering) Moist skin

Respiratory System Moist membranes, gills in larvae, lungs in adult

Circulatory System 3 chamber heart

Body Temperature Regulation Ectothermic

Reproductive Fertilization & Embryo Development

External, large # of eggs laid in water, metamorphosis

Special Adaptations Lungs, webbed feet, bridge b/w land & water animals

Amphibians

Characteristics of Amphibians

Thin, moist skin 4 legs (except for the apoda) No claws on their toes Most live on land as adults Require water for reproduction Fertilization is usually external Water is needed to transport sperm so eggs are

usually laid in water No protective membranes or shells on their eggs

Differences between a Frog and Toad Frog

Generally have smooth, moist skin

Longer hind legs (for swimming and leaping)

Webbed hind feet Lay eggs in a clump

that is a cloudy, jellylike mass

Toad Generally have warty,

dry skin Shorter hind legs (for

walking rather than marathon hopping)

More terrestrial Lay eggs in stringy

chains

Reptiles

Examples Snakes, lizards, turtles, gators/crocs

Habitat Landoften dry, mostly warm

Integument (covering) Scales, shells

Respiratory System Well-developed lungs

Circulatory System 3 chamber heart

4 chamber heart (all crocs)

Body Temperature Regulation

ectothermic

Reproductive Fertilization & Embryo Development

Internal, amniotic eggs, fewer eggs

Special Adaptations

Reptiles

Differences between a Amphibians and Reptiles Amphibians

Moist skin Often webbed feet

(never clawed) Skin is smooth or

bumpy, but must stay wet

Ex: frogs, toads, newts, salamanders, and caecilians

Reptiles Dry, scaly skin Clawed feet Lungs Ex: alligators,

crocodiles, lizards, tortoises, and turtles

Differences between a Crocodile and Alligator Crocodiles

Narrow, V-shaped snouts

Upper and lower jaws roughly same width

Both upper and lower teeth jut out when their mouth is closed

4th lower tooth of each side sticks out prominently

Alligators Broad, U-shaped

snouts Upper jaw overlaps

their lower jaw Upper teeth are

visible, lower teeth hidden

Birds

Examples Flapping, non-flapping (gliding & soaring)

Habitat Land warm & cold areas

Integument (covering) feathers

Respiratory System Lungs with air sacs

Circulatory System 4 chamber heart

Body Temperature Regulation Endothermic (warm blooded)- regulate own temperature independent of surroundings

Reproductive Fertilization & Embryo Development

Internal, amniotic eggs, fewer eggs

Special Adaptations Flight with wings & hollow bones, beak, foot adaptations

Birds

Mammals

Examples Egg laying, pouched, placental, flying-bat

Habitat Land and water warm & cold areas

Integument (covering) Skin, hair or fur, scales

Respiratory System Lungs and diaphragm

Circulatory System 4 chamber heart

Body Temperature Regulation Endothermic

Reproductive Fertilization & Embryo Development

Internal, live birth for placental & pouches, or eggs

Special Adaptations Mammary glands, large brain, teeth, nearly all habitats

Mammals